1. Field of the Invention
The invention concerns a single-substrate processing CVD apparatus and a single-substrate processing CVD procedure and, in particular, it concerns a single-substrate processing CVD apparatus and a single-substrate processing CVD procedure whereby a metal film for wiring purposes is deposited using a plurality of CVD film deposition modules in order to form a highly integrated circuit device on a silicon or glass substrate.
2. Description of Related Art
Only experimental copper CVD (chemical vapor growth or chemical vapor deposition) apparatus for depositing copper films for wiring purposes of semiconductor highly integrated circuit devices have been made in the past, and a single-substrate processing copper CVD apparatus for volume manufacture has not as yet been provided successfully. A copper film for wiring purposes is to be deposited on a silicon, compound semiconductor or glass substrate in a single-substrate processing copper CVD apparatus for volume manufacture purposes. There is a need (a) to increase the rate of deposition of the film and raise the film deposition efficiency and (b) to improve the filling characteristics for step coverage and to improve the quality of the film in the single-substrate processing copper CVD apparatus for volume manufacture purposes.
Much research has been carried out in the past in connection with the process order of the optimum film deposition process in single-substrate processing copper CVD apparatus, the number of processes, and the number of film deposition modules and their construction from the viewpoints of achieving a higher film deposition efficiency and higher film quality. However, as yet no ideal film deposition module for single-substrate processing copper CVD apparatus for volume manufacture purposes has been verified
Thus if, in the case of copper CVD, a copper film is deposited in a single process (with one set of film deposition conditions in one film depositing chamber) then there is a trade-off between the film deposition rate and the filling characteristics of the film. It is very difficult to carry out film deposition in such a way as to provide a satisfactory film deposition rate and satisfactory filling characteristics with single process copper CVD. Up to the present time no practical single-substrate processing copper CVD apparatus for volume manufacture purposes has been realized.
An aim of the present invention is to resolve the problems described above and to provide a single-substrate processing CVD apparatus and a single-substrate processing CVD procedure whereby a high film deposition rate and good filling characteristics can be realized and with which both the film deposition efficiency and the film quality are improved in a single-substrate processing CVD apparatus where a metal film for wiring purposes is being deposited on a substrate.
The single-substrate processing CVD apparatus and the single-substrate processing CVD procedure of the present invention are constituted in the ways indicated below for realizing the aforementioned aims.
The single-substrate processing CVD apparatus of the present invention is a cluster-tool type apparatus is (multi-chamber type apparatus) with which a metal film for wiring purposes is deposited on a substrate. The single-substrate processing CVD apparatus is furnished with a first CVD module in which film deposition is carried out under first deposition conditions where the film deposition rate is relatively low and the filling characteristics are good and a second CVD module in which film deposition is carried out under second deposition conditions where the film deposition rate is relatively high and the filling characteristics are poor.
In the CVD apparatus of the present invention, use is made of the fact that when the film deposition temperature (substrate temperature) is set relatively low (first deposition conditions), the rate of film deposition is relatively low and the filling characteristics for step coverage are relatively good. Moreover, in the CVD apparatus of the present invention, use is made of the fact that when the aforementioned film deposition temperature (substrate temperature) is set relatively high (second deposition conditions), the rate of film deposition is relatively high and the embedding characteristics for step coverage are not as good as with the first deposition conditions. The system is such that one CVD process for depositing a metal film for wiring purposes is divided into sub-processes on the basis of two sets of film deposition conditions, and the sub-processes are carried out in first and second CVD module respectively. Hence, the single-substrate processing CVD apparatus of the present invention is suitable for the volume manufacture of semiconductor wafer fabrication equipment with which an increase in film deposition efficiency and improvement in film quality can be realized.
One film deposition procedure is completed by combining a film deposition process which is carried out under first film deposition conditions and a film deposition process which is carried out under second film deposition conditions. The CVD apparatus of this invention has at least two CVD modules corresponding to each set of film deposition conditions.
The first CVD module and the second CVD module are both thermal CVD modules. The precursor used in the first CVD module and the second CVD module is preferably a xcex2-diketonato-copper(I) complex. Trimethylvinylsilyl-hexafluoroacetylacetonato-copper(I) can be used for the precursor xcex2-diketonato-copper(I) complex. Under the first film deposition conditions, the substrate temperature is preferably set to a temperature within the range of about 150 to 190xc2x0 C. and under the second film deposition conditions, the substrate temperature is preferably set to a temperature within the range of about 190 to 230xc2x0 C. The difference between the substrate temperatures under the first and second film deposition conditions is preferably at least 5xc2x0 C.
Another single-substrate processing CVD procedure of the present invention is a procedure whereby a metal film for wiring purposes is deposited on a substrate by means of a combination of a first CVD process and a second CVD process, which have different film deposition conditions as one film deposition process. In the first CVD process a film is deposited under first film deposition conditions where the film deposition rate is relatively low and the filling characteristics are good. In the second CVD process a film is deposited under second film deposition conditions where the film deposition rate is relatively high and the filling characteristics are not as good as the first film deposition conditions. In the CVD procedure of the present invention, the first CVD process and the second CVD process are executed sequentially. The order in which the first CVD process and the second CVD process are carried out is determined in accordance with the form of the wiring pattern for which the film deposition process is being carried out. When the form of the wiring pattern is relatively small, the first CVD process is carried out first and then the second CVD process is carried out. When the form of the wiring pattern is relatively large, the second CVD process is carried out first and then the first CVD process is carried out.
The first and second CVD processes are both thermal CVD processes. The precursor used in the first CVD process and the second CVD process is preferably a xcex2-diketonato-copper(I) complex. Trimethylvinylsilyl-hexafluoroacetylacetonato-copper(I) can be used for the precursor xcex2-diketonato-copper(I) complex. Under the first film deposition conditions, the substrate temperature is preferably set to a temperature within the range of about 150 to 190xc2x0 C. and under the second film deposition conditions, the substrate temperature is preferably set to a temperature within the range of about 190 to 230xc2x0 C. The difference between the substrate temperatures under the first and second film deposition conditions is at least 5xc2x0 C.